Squashed 'waflib/' content from commit 982416b

git-subtree-dir: waflib
git-subtree-split: 982416b8a6c6728e200243e1be3ab60435c08830

1 files changed, 1351 insertions, 0 deletions

diff --git a/Tools/c_config.py b/Tools/c_config.py
new file mode 100644
index 0000000..d2b3c0d
--- /dev/null
+++ b/Tools/c_config.py
@@ -0,0 +1,1351 @@
+#!/usr/bin/env python
+# encoding: utf-8
+# Thomas Nagy, 2005-2018 (ita)
+
+"""
+C/C++/D configuration helpers
+"""
+
+from __future__ import with_statement
+
+import os, re, shlex
+from waflib import Build, Utils, Task, Options, Logs, Errors, Runner
+from waflib.TaskGen import after_method, feature
+from waflib.Configure import conf
+
+WAF_CONFIG_H   = 'config.h'
+"""default name for the config.h file"""
+
+DEFKEYS = 'define_key'
+INCKEYS = 'include_key'
+
+SNIP_EMPTY_PROGRAM = '''
+int main(int argc, char **argv) {
+	(void)argc; (void)argv;
+	return 0;
+}
+'''
+
+MACRO_TO_DESTOS = {
+'__linux__'                                      : 'linux',
+'__GNU__'                                        : 'gnu', # hurd
+'__FreeBSD__'                                    : 'freebsd',
+'__NetBSD__'                                     : 'netbsd',
+'__OpenBSD__'                                    : 'openbsd',
+'__sun'                                          : 'sunos',
+'__hpux'                                         : 'hpux',
+'__sgi'                                          : 'irix',
+'_AIX'                                           : 'aix',
+'__CYGWIN__'                                     : 'cygwin',
+'__MSYS__'                                       : 'cygwin',
+'_UWIN'                                          : 'uwin',
+'_WIN64'                                         : 'win32',
+'_WIN32'                                         : 'win32',
+# Note about darwin: this is also tested with 'defined __APPLE__ && defined __MACH__' somewhere below in this file.
+'__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__'  : 'darwin',
+'__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__' : 'darwin', # iphone
+'__QNX__'                                        : 'qnx',
+'__native_client__'                              : 'nacl' # google native client platform
+}
+
+MACRO_TO_DEST_CPU = {
+'__x86_64__'  : 'x86_64',
+'__amd64__'   : 'x86_64',
+'__i386__'    : 'x86',
+'__ia64__'    : 'ia',
+'__mips__'    : 'mips',
+'__sparc__'   : 'sparc',
+'__alpha__'   : 'alpha',
+'__aarch64__' : 'aarch64',
+'__thumb__'   : 'thumb',
+'__arm__'     : 'arm',
+'__hppa__'    : 'hppa',
+'__powerpc__' : 'powerpc',
+'__ppc__'     : 'powerpc',
+'__convex__'  : 'convex',
+'__m68k__'    : 'm68k',
+'__s390x__'   : 's390x',
+'__s390__'    : 's390',
+'__sh__'      : 'sh',
+'__xtensa__'  : 'xtensa',
+}
+
+@conf
+def parse_flags(self, line, uselib_store, env=None, force_static=False, posix=None):
+	"""
+	Parses flags from the input lines, and adds them to the relevant use variables::
+
+		def configure(conf):
+			conf.parse_flags('-O3', 'FOO')
+			# conf.env.CXXFLAGS_FOO = ['-O3']
+			# conf.env.CFLAGS_FOO = ['-O3']
+
+	:param line: flags
+	:type line: string
+	:param uselib_store: where to add the flags
+	:type uselib_store: string
+	:param env: config set or conf.env by default
+	:type env: :py:class:`waflib.ConfigSet.ConfigSet`
+	"""
+
+	assert(isinstance(line, str))
+
+	env = env or self.env
+
+	# Issue 811 and 1371
+	if posix is None:
+		posix = True
+		if '\\' in line:
+			posix = ('\\ ' in line) or ('\\\\' in line)
+
+	lex = shlex.shlex(line, posix=posix)
+	lex.whitespace_split = True
+	lex.commenters = ''
+	lst = list(lex)
+
+	# append_unique is not always possible
+	# for example, apple flags may require both -arch i386 and -arch ppc
+	uselib = uselib_store
+	def app(var, val):
+		env.append_value('%s_%s' % (var, uselib), val)
+	def appu(var, val):
+		env.append_unique('%s_%s' % (var, uselib), val)
+	static = False
+	while lst:
+		x = lst.pop(0)
+		st = x[:2]
+		ot = x[2:]
+
+		if st == '-I' or st == '/I':
+			if not ot:
+				ot = lst.pop(0)
+			appu('INCLUDES', ot)
+		elif st == '-i':
+			tmp = [x, lst.pop(0)]
+			app('CFLAGS', tmp)
+			app('CXXFLAGS', tmp)
+		elif st == '-D' or (env.CXX_NAME == 'msvc' and st == '/D'): # not perfect but..
+			if not ot:
+				ot = lst.pop(0)
+			app('DEFINES', ot)
+		elif st == '-l':
+			if not ot:
+				ot = lst.pop(0)
+			prefix = 'STLIB' if (force_static or static) else 'LIB'
+			app(prefix, ot)
+		elif st == '-L':
+			if not ot:
+				ot = lst.pop(0)
+			prefix = 'STLIBPATH' if (force_static or static) else 'LIBPATH'
+			appu(prefix, ot)
+		elif x.startswith('/LIBPATH:'):
+			prefix = 'STLIBPATH' if (force_static or static) else 'LIBPATH'
+			appu(prefix, x.replace('/LIBPATH:', ''))
+		elif x.startswith('-std='):
+			prefix = 'CXXFLAGS' if '++' in x else 'CFLAGS'
+			app(prefix, x)
+		elif x.startswith('+') or x in ('-pthread', '-fPIC', '-fpic', '-fPIE', '-fpie'):
+			app('CFLAGS', x)
+			app('CXXFLAGS', x)
+			app('LINKFLAGS', x)
+		elif x == '-framework':
+			appu('FRAMEWORK', lst.pop(0))
+		elif x.startswith('-F'):
+			appu('FRAMEWORKPATH', x[2:])
+		elif x == '-Wl,-rpath' or x == '-Wl,-R':
+			app('RPATH', lst.pop(0).lstrip('-Wl,'))
+		elif x.startswith('-Wl,-R,'):
+			app('RPATH', x[7:])
+		elif x.startswith('-Wl,-R'):
+			app('RPATH', x[6:])
+		elif x.startswith('-Wl,-rpath,'):
+			app('RPATH', x[11:])
+		elif x == '-Wl,-Bstatic' or x == '-Bstatic':
+			static = True
+		elif x == '-Wl,-Bdynamic' or x == '-Bdynamic':
+			static = False
+		elif x.startswith('-Wl') or x in ('-rdynamic', '-pie'):
+			app('LINKFLAGS', x)
+		elif x.startswith(('-m', '-f', '-dynamic', '-O', '-g')):
+			# Adding the -W option breaks python builds on Openindiana
+			app('CFLAGS', x)
+			app('CXXFLAGS', x)
+		elif x.startswith('-bundle'):
+			app('LINKFLAGS', x)
+		elif x.startswith(('-undefined', '-Xlinker')):
+			arg = lst.pop(0)
+			app('LINKFLAGS', [x, arg])
+		elif x.startswith(('-arch', '-isysroot')):
+			tmp = [x, lst.pop(0)]
+			app('CFLAGS', tmp)
+			app('CXXFLAGS', tmp)
+			app('LINKFLAGS', tmp)
+		elif x.endswith(('.a', '.so', '.dylib', '.lib')):
+			appu('LINKFLAGS', x) # not cool, #762
+		else:
+			self.to_log('Unhandled flag %r' % x)
+
+@conf
+def validate_cfg(self, kw):
+	"""
+	Searches for the program *pkg-config* if missing, and validates the
+	parameters to pass to :py:func:`waflib.Tools.c_config.exec_cfg`.
+
+	:param path: the **-config program to use** (default is *pkg-config*)
+	:type path: list of string
+	:param msg: message to display to describe the test executed
+	:type msg: string
+	:param okmsg: message to display when the test is successful
+	:type okmsg: string
+	:param errmsg: message to display in case of error
+	:type errmsg: string
+	"""
+	if not 'path' in kw:
+		if not self.env.PKGCONFIG:
+			self.find_program('pkg-config', var='PKGCONFIG')
+		kw['path'] = self.env.PKGCONFIG
+
+	# verify that exactly one action is requested
+	s = ('atleast_pkgconfig_version' in kw) + ('modversion' in kw) + ('package' in kw)
+	if s != 1:
+		raise ValueError('exactly one of atleast_pkgconfig_version, modversion and package must be set')
+	if not 'msg' in kw:
+		if 'atleast_pkgconfig_version' in kw:
+			kw['msg'] = 'Checking for pkg-config version >= %r' % kw['atleast_pkgconfig_version']
+		elif 'modversion' in kw:
+			kw['msg'] = 'Checking for %r version' % kw['modversion']
+		else:
+			kw['msg'] = 'Checking for %r' %(kw['package'])
+
+	# let the modversion check set the okmsg to the detected version
+	if not 'okmsg' in kw and not 'modversion' in kw:
+		kw['okmsg'] = 'yes'
+	if not 'errmsg' in kw:
+		kw['errmsg'] = 'not found'
+
+	# pkg-config version
+	if 'atleast_pkgconfig_version' in kw:
+		pass
+	elif 'modversion' in kw:
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = kw['modversion']
+		if not 'define_name' in kw:
+			kw['define_name'] = '%s_VERSION' % Utils.quote_define_name(kw['uselib_store'])
+	else:
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = Utils.to_list(kw['package'])[0].upper()
+		if not 'define_name' in kw:
+			kw['define_name'] = self.have_define(kw['uselib_store'])
+
+@conf
+def exec_cfg(self, kw):
+	"""
+	Executes ``pkg-config`` or other ``-config`` applications to collect configuration flags:
+
+	* if atleast_pkgconfig_version is given, check that pkg-config has the version n and return
+	* if modversion is given, then return the module version
+	* else, execute the *-config* program with the *args* and *variables* given, and set the flags on the *conf.env.FLAGS_name* variable
+
+	:param atleast_pkgconfig_version: minimum pkg-config version to use (disable other tests)
+	:type atleast_pkgconfig_version: string
+	:param package: package name, for example *gtk+-2.0*
+	:type package: string
+	:param uselib_store: if the test is successful, define HAVE\_*name*. It is also used to define *conf.env.FLAGS_name* variables.
+	:type uselib_store: string
+	:param modversion: if provided, return the version of the given module and define *name*\_VERSION
+	:type modversion: string
+	:param args: arguments to give to *package* when retrieving flags
+	:type args: list of string
+	:param variables: return the values of particular variables
+	:type variables: list of string
+	:param define_variable: additional variables to define (also in conf.env.PKG_CONFIG_DEFINES)
+	:type define_variable: dict(string: string)
+	"""
+
+	path = Utils.to_list(kw['path'])
+	env = self.env.env or None
+	if kw.get('pkg_config_path'):
+		if not env:
+			env = dict(self.environ)
+		env['PKG_CONFIG_PATH'] = kw['pkg_config_path']
+
+	def define_it():
+		define_name = kw['define_name']
+		# by default, add HAVE_X to the config.h, else provide DEFINES_X for use=X
+		if kw.get('global_define', 1):
+			self.define(define_name, 1, False)
+		else:
+			self.env.append_unique('DEFINES_%s' % kw['uselib_store'], "%s=1" % define_name)
+
+		if kw.get('add_have_to_env', 1):
+			self.env[define_name] = 1
+
+	# pkg-config version
+	if 'atleast_pkgconfig_version' in kw:
+		cmd = path + ['--atleast-pkgconfig-version=%s' % kw['atleast_pkgconfig_version']]
+		self.cmd_and_log(cmd, env=env)
+		return
+
+	# single version for a module
+	if 'modversion' in kw:
+		version = self.cmd_and_log(path + ['--modversion', kw['modversion']], env=env).strip()
+		if not 'okmsg' in kw:
+			kw['okmsg'] = version
+		self.define(kw['define_name'], version)
+		return version
+
+	lst = [] + path
+
+	defi = kw.get('define_variable')
+	if not defi:
+		defi = self.env.PKG_CONFIG_DEFINES or {}
+	for key, val in defi.items():
+		lst.append('--define-variable=%s=%s' % (key, val))
+
+	static = kw.get('force_static', False)
+	if 'args' in kw:
+		args = Utils.to_list(kw['args'])
+		if '--static' in args or '--static-libs' in args:
+			static = True
+		lst += args
+
+	# tools like pkgconf expect the package argument after the -- ones -_-
+	lst.extend(Utils.to_list(kw['package']))
+
+	# retrieving variables of a module
+	if 'variables' in kw:
+		v_env = kw.get('env', self.env)
+		vars = Utils.to_list(kw['variables'])
+		for v in vars:
+			val = self.cmd_and_log(lst + ['--variable=' + v], env=env).strip()
+			var = '%s_%s' % (kw['uselib_store'], v)
+			v_env[var] = val
+		return
+
+	# so we assume the command-line will output flags to be parsed afterwards
+	ret = self.cmd_and_log(lst, env=env)
+
+	define_it()
+	self.parse_flags(ret, kw['uselib_store'], kw.get('env', self.env), force_static=static, posix=kw.get('posix'))
+	return ret
+
+@conf
+def check_cfg(self, *k, **kw):
+	"""
+	Checks for configuration flags using a **-config**-like program (pkg-config, sdl-config, etc).
+	This wraps internal calls to :py:func:`waflib.Tools.c_config.validate_cfg` and :py:func:`waflib.Tools.c_config.exec_cfg`
+
+	A few examples::
+
+		def configure(conf):
+			conf.load('compiler_c')
+			conf.check_cfg(package='glib-2.0', args='--libs --cflags')
+			conf.check_cfg(package='pango')
+			conf.check_cfg(package='pango', uselib_store='MYPANGO', args=['--cflags', '--libs'])
+			conf.check_cfg(package='pango',
+				args=['pango >= 0.1.0', 'pango < 9.9.9', '--cflags', '--libs'],
+				msg="Checking for 'pango 0.1.0'")
+			conf.check_cfg(path='sdl-config', args='--cflags --libs', package='', uselib_store='SDL')
+			conf.check_cfg(path='mpicc', args='--showme:compile --showme:link',
+				package='', uselib_store='OPEN_MPI', mandatory=False)
+			# variables
+			conf.check_cfg(package='gtk+-2.0', variables=['includedir', 'prefix'], uselib_store='FOO')
+			print(conf.env.FOO_includedir)
+	"""
+	self.validate_cfg(kw)
+	if 'msg' in kw:
+		self.start_msg(kw['msg'], **kw)
+	ret = None
+	try:
+		ret = self.exec_cfg(kw)
+	except self.errors.WafError as e:
+		if 'errmsg' in kw:
+			self.end_msg(kw['errmsg'], 'YELLOW', **kw)
+		if Logs.verbose > 1:
+			self.to_log('Command failure: %s' % e)
+		self.fatal('The configuration failed')
+	else:
+		if not ret:
+			ret = True
+		kw['success'] = ret
+		if 'okmsg' in kw:
+			self.end_msg(self.ret_msg(kw['okmsg'], kw), **kw)
+
+	return ret
+
+def build_fun(bld):
+	"""
+	Build function that is used for running configuration tests with ``conf.check()``
+	"""
+	if bld.kw['compile_filename']:
+		node = bld.srcnode.make_node(bld.kw['compile_filename'])
+		node.write(bld.kw['code'])
+
+	o = bld(features=bld.kw['features'], source=bld.kw['compile_filename'], target='testprog')
+
+	for k, v in bld.kw.items():
+		setattr(o, k, v)
+
+	if not bld.kw.get('quiet'):
+		bld.conf.to_log("==>\n%s\n<==" % bld.kw['code'])
+
+@conf
+def validate_c(self, kw):
+	"""
+	Pre-checks the parameters that will be given to :py:func:`waflib.Configure.run_build`
+
+	:param compiler: c or cxx (tries to guess what is best)
+	:type compiler: string
+	:param type: cprogram, cshlib, cstlib - not required if *features are given directly*
+	:type type: binary to create
+	:param feature: desired features for the task generator that will execute the test, for example ``cxx cxxstlib``
+	:type feature: list of string
+	:param fragment: provide a piece of code for the test (default is to let the system create one)
+	:type fragment: string
+	:param uselib_store: define variables after the test is executed (IMPORTANT!)
+	:type uselib_store: string
+	:param use: parameters to use for building (just like the normal *use* keyword)
+	:type use: list of string
+	:param define_name: define to set when the check is over
+	:type define_name: string
+	:param execute: execute the resulting binary
+	:type execute: bool
+	:param define_ret: if execute is set to True, use the execution output in both the define and the return value
+	:type define_ret: bool
+	:param header_name: check for a particular header
+	:type header_name: string
+	:param auto_add_header_name: if header_name was set, add the headers in env.INCKEYS so the next tests will include these headers
+	:type auto_add_header_name: bool
+	"""
+	for x in ('type_name', 'field_name', 'function_name'):
+		if x in kw:
+			Logs.warn('Invalid argument %r in test' % x)
+
+	if not 'build_fun' in kw:
+		kw['build_fun'] = build_fun
+
+	if not 'env' in kw:
+		kw['env'] = self.env.derive()
+	env = kw['env']
+
+	if not 'compiler' in kw and not 'features' in kw:
+		kw['compiler'] = 'c'
+		if env.CXX_NAME and Task.classes.get('cxx'):
+			kw['compiler'] = 'cxx'
+			if not self.env.CXX:
+				self.fatal('a c++ compiler is required')
+		else:
+			if not self.env.CC:
+				self.fatal('a c compiler is required')
+
+	if not 'compile_mode' in kw:
+		kw['compile_mode'] = 'c'
+		if 'cxx' in Utils.to_list(kw.get('features', [])) or kw.get('compiler') == 'cxx':
+			kw['compile_mode'] = 'cxx'
+
+	if not 'type' in kw:
+		kw['type'] = 'cprogram'
+
+	if not 'features' in kw:
+		if not 'header_name' in kw or kw.get('link_header_test', True):
+			kw['features'] = [kw['compile_mode'], kw['type']] # "c ccprogram"
+		else:
+			kw['features'] = [kw['compile_mode']]
+	else:
+		kw['features'] = Utils.to_list(kw['features'])
+
+	if not 'compile_filename' in kw:
+		kw['compile_filename'] = 'test.c' + ((kw['compile_mode'] == 'cxx') and 'pp' or '')
+
+	def to_header(dct):
+		if 'header_name' in dct:
+			dct = Utils.to_list(dct['header_name'])
+			return ''.join(['#include <%s>\n' % x for x in dct])
+		return ''
+
+	if 'framework_name' in kw:
+		# OSX, not sure this is used anywhere
+		fwkname = kw['framework_name']
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = fwkname.upper()
+		if not kw.get('no_header'):
+			fwk = '%s/%s.h' % (fwkname, fwkname)
+			if kw.get('remove_dot_h'):
+				fwk = fwk[:-2]
+			val = kw.get('header_name', [])
+			kw['header_name'] = Utils.to_list(val) + [fwk]
+		kw['msg'] = 'Checking for framework %s' % fwkname
+		kw['framework'] = fwkname
+
+	elif 'header_name' in kw:
+		if not 'msg' in kw:
+			kw['msg'] = 'Checking for header %s' % kw['header_name']
+
+		l = Utils.to_list(kw['header_name'])
+		assert len(l), 'list of headers in header_name is empty'
+
+		kw['code'] = to_header(kw) + SNIP_EMPTY_PROGRAM
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = l[0].upper()
+		if not 'define_name' in kw:
+			kw['define_name'] = self.have_define(l[0])
+
+	if 'lib' in kw:
+		if not 'msg' in kw:
+			kw['msg'] = 'Checking for library %s' % kw['lib']
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = kw['lib'].upper()
+
+	if 'stlib' in kw:
+		if not 'msg' in kw:
+			kw['msg'] = 'Checking for static library %s' % kw['stlib']
+		if not 'uselib_store' in kw:
+			kw['uselib_store'] = kw['stlib'].upper()
+
+	if 'fragment' in kw:
+		# an additional code fragment may be provided to replace the predefined code
+		# in custom headers
+		kw['code'] = kw['fragment']
+		if not 'msg' in kw:
+			kw['msg'] = 'Checking for code snippet'
+		if not 'errmsg' in kw:
+			kw['errmsg'] = 'no'
+
+	for (flagsname,flagstype) in (('cxxflags','compiler'), ('cflags','compiler'), ('linkflags','linker')):
+		if flagsname in kw:
+			if not 'msg' in kw:
+				kw['msg'] = 'Checking for %s flags %s' % (flagstype, kw[flagsname])
+			if not 'errmsg' in kw:
+				kw['errmsg'] = 'no'
+
+	if not 'execute' in kw:
+		kw['execute'] = False
+	if kw['execute']:
+		kw['features'].append('test_exec')
+		kw['chmod'] = Utils.O755
+
+	if not 'errmsg' in kw:
+		kw['errmsg'] = 'not found'
+
+	if not 'okmsg' in kw:
+		kw['okmsg'] = 'yes'
+
+	if not 'code' in kw:
+		kw['code'] = SNIP_EMPTY_PROGRAM
+
+	# if there are headers to append automatically to the next tests
+	if self.env[INCKEYS]:
+		kw['code'] = '\n'.join(['#include <%s>' % x for x in self.env[INCKEYS]]) + '\n' + kw['code']
+
+	# in case defines lead to very long command-lines
+	if kw.get('merge_config_header') or env.merge_config_header:
+		kw['code'] = '%s\n\n%s' % (self.get_config_header(), kw['code'])
+		env.DEFINES = [] # modify the copy
+
+	if not kw.get('success'):
+		kw['success'] = None
+
+	if 'define_name' in kw:
+		self.undefine(kw['define_name'])
+	if not 'msg' in kw:
+		self.fatal('missing "msg" in conf.check(...)')
+
+@conf
+def post_check(self, *k, **kw):
+	"""
+	Sets the variables after a test executed in
+	:py:func:`waflib.Tools.c_config.check` was run successfully
+	"""
+	is_success = 0
+	if kw['execute']:
+		if kw['success'] is not None:
+			if kw.get('define_ret'):
+				is_success = kw['success']
+			else:
+				is_success = (kw['success'] == 0)
+	else:
+		is_success = (kw['success'] == 0)
+
+	if kw.get('define_name'):
+		comment = kw.get('comment', '')
+		define_name = kw['define_name']
+		if kw['execute'] and kw.get('define_ret') and isinstance(is_success, str):
+			if kw.get('global_define', 1):
+				self.define(define_name, is_success, quote=kw.get('quote', 1), comment=comment)
+			else:
+				if kw.get('quote', 1):
+					succ = '"%s"' % is_success
+				else:
+					succ = int(is_success)
+				val = '%s=%s' % (define_name, succ)
+				var = 'DEFINES_%s' % kw['uselib_store']
+				self.env.append_value(var, val)
+		else:
+			if kw.get('global_define', 1):
+				self.define_cond(define_name, is_success, comment=comment)
+			else:
+				var = 'DEFINES_%s' % kw['uselib_store']
+				self.env.append_value(var, '%s=%s' % (define_name, int(is_success)))
+
+		# define conf.env.HAVE_X to 1
+		if kw.get('add_have_to_env', 1):
+			if kw.get('uselib_store'):
+				self.env[self.have_define(kw['uselib_store'])] = 1
+			elif kw['execute'] and kw.get('define_ret'):
+				self.env[define_name] = is_success
+			else:
+				self.env[define_name] = int(is_success)
+
+	if 'header_name' in kw:
+		if kw.get('auto_add_header_name'):
+			self.env.append_value(INCKEYS, Utils.to_list(kw['header_name']))
+
+	if is_success and 'uselib_store' in kw:
+		from waflib.Tools import ccroot
+		# See get_uselib_vars in ccroot.py
+		_vars = set()
+		for x in kw['features']:
+			if x in ccroot.USELIB_VARS:
+				_vars |= ccroot.USELIB_VARS[x]
+
+		for k in _vars:
+			x = k.lower()
+			if x in kw:
+				self.env.append_value(k + '_' + kw['uselib_store'], kw[x])
+	return is_success
+
+@conf
+def check(self, *k, **kw):
+	"""
+	Performs a configuration test by calling :py:func:`waflib.Configure.run_build`.
+	For the complete list of parameters, see :py:func:`waflib.Tools.c_config.validate_c`.
+	To force a specific compiler, pass ``compiler='c'`` or ``compiler='cxx'`` to the list of arguments
+
+	Besides build targets, complete builds can be given through a build function. All files will
+	be written to a temporary directory::
+
+		def build(bld):
+			lib_node = bld.srcnode.make_node('libdir/liblc1.c')
+			lib_node.parent.mkdir()
+			lib_node.write('#include <stdio.h>\\nint lib_func(void) { FILE *f = fopen("foo", "r");}\\n', 'w')
+			bld(features='c cshlib', source=[lib_node], linkflags=conf.env.EXTRA_LDFLAGS, target='liblc')
+		conf.check(build_fun=build, msg=msg)
+	"""
+	self.validate_c(kw)
+	self.start_msg(kw['msg'], **kw)
+	ret = None
+	try:
+		ret = self.run_build(*k, **kw)
+	except self.errors.ConfigurationError:
+		self.end_msg(kw['errmsg'], 'YELLOW', **kw)
+		if Logs.verbose > 1:
+			raise
+		else:
+			self.fatal('The configuration failed')
+	else:
+		kw['success'] = ret
+
+	ret = self.post_check(*k, **kw)
+	if not ret:
+		self.end_msg(kw['errmsg'], 'YELLOW', **kw)
+		self.fatal('The configuration failed %r' % ret)
+	else:
+		self.end_msg(self.ret_msg(kw['okmsg'], kw), **kw)
+	return ret
+
+class test_exec(Task.Task):
+	"""
+	A task that runs programs after they are built. See :py:func:`waflib.Tools.c_config.test_exec_fun`.
+	"""
+	color = 'PINK'
+	def run(self):
+		if getattr(self.generator, 'rpath', None):
+			if getattr(self.generator, 'define_ret', False):
+				self.generator.bld.retval = self.generator.bld.cmd_and_log([self.inputs[0].abspath()])
+			else:
+				self.generator.bld.retval = self.generator.bld.exec_command([self.inputs[0].abspath()])
+		else:
+			env = self.env.env or {}
+			env.update(dict(os.environ))
+			for var in ('LD_LIBRARY_PATH', 'DYLD_LIBRARY_PATH', 'PATH'):
+				env[var] = self.inputs[0].parent.abspath() + os.path.pathsep + env.get(var, '')
+			if getattr(self.generator, 'define_ret', False):
+				self.generator.bld.retval = self.generator.bld.cmd_and_log([self.inputs[0].abspath()], env=env)
+			else:
+				self.generator.bld.retval = self.generator.bld.exec_command([self.inputs[0].abspath()], env=env)
+
+@feature('test_exec')
+@after_method('apply_link')
+def test_exec_fun(self):
+	"""
+	The feature **test_exec** is used to create a task that will to execute the binary
+	created (link task output) during the build. The exit status will be set
+	on the build context, so only one program may have the feature *test_exec*.
+	This is used by configuration tests::
+
+		def configure(conf):
+			conf.check(execute=True)
+	"""
+	self.create_task('test_exec', self.link_task.outputs[0])
+
+@conf
+def check_cxx(self, *k, **kw):
+	"""
+	Runs a test with a task generator of the form::
+
+		conf.check(features='cxx cxxprogram', ...)
+	"""
+	kw['compiler'] = 'cxx'
+	return self.check(*k, **kw)
+
+@conf
+def check_cc(self, *k, **kw):
+	"""
+	Runs a test with a task generator of the form::
+
+		conf.check(features='c cprogram', ...)
+	"""
+	kw['compiler'] = 'c'
+	return self.check(*k, **kw)
+
+@conf
+def set_define_comment(self, key, comment):
+	"""
+	Sets a comment that will appear in the configuration header
+
+	:type key: string
+	:type comment: string
+	"""
+	coms = self.env.DEFINE_COMMENTS
+	if not coms:
+		coms = self.env.DEFINE_COMMENTS = {}
+	coms[key] = comment or ''
+
+@conf
+def get_define_comment(self, key):
+	"""
+	Returns the comment associated to a define
+
+	:type key: string
+	"""
+	coms = self.env.DEFINE_COMMENTS or {}
+	return coms.get(key, '')
+
+@conf
+def define(self, key, val, quote=True, comment=''):
+	"""
+	Stores a single define and its state into ``conf.env.DEFINES``. The value is cast to an integer (0/1).
+
+	:param key: define name
+	:type key: string
+	:param val: value
+	:type val: int or string
+	:param quote: enclose strings in quotes (yes by default)
+	:type quote: bool
+	"""
+	assert isinstance(key, str)
+	if not key:
+		return
+	if val is True:
+		val = 1
+	elif val in (False, None):
+		val = 0
+
+	if isinstance(val, int) or isinstance(val, float):
+		s = '%s=%s'
+	else:
+		s = quote and '%s="%s"' or '%s=%s'
+	app = s % (key, str(val))
+
+	ban = key + '='
+	lst = self.env.DEFINES
+	for x in lst:
+		if x.startswith(ban):
+			lst[lst.index(x)] = app
+			break
+	else:
+		self.env.append_value('DEFINES', app)
+
+	self.env.append_unique(DEFKEYS, key)
+	self.set_define_comment(key, comment)
+
+@conf
+def undefine(self, key, comment=''):
+	"""
+	Removes a global define from ``conf.env.DEFINES``
+
+	:param key: define name
+	:type key: string
+	"""
+	assert isinstance(key, str)
+	if not key:
+		return
+	ban = key + '='
+	lst = [x for x in self.env.DEFINES if not x.startswith(ban)]
+	self.env.DEFINES = lst
+	self.env.append_unique(DEFKEYS, key)
+	self.set_define_comment(key, comment)
+
+@conf
+def define_cond(self, key, val, comment=''):
+	"""
+	Conditionally defines a name::
+
+		def configure(conf):
+			conf.define_cond('A', True)
+			# equivalent to:
+			# if val: conf.define('A', 1)
+			# else: conf.undefine('A')
+
+	:param key: define name
+	:type key: string
+	:param val: value
+	:type val: int or string
+	"""
+	assert isinstance(key, str)
+	if not key:
+		return
+	if val:
+		self.define(key, 1, comment=comment)
+	else:
+		self.undefine(key, comment=comment)
+
+@conf
+def is_defined(self, key):
+	"""
+	Indicates whether a particular define is globally set in ``conf.env.DEFINES``.
+
+	:param key: define name
+	:type key: string
+	:return: True if the define is set
+	:rtype: bool
+	"""
+	assert key and isinstance(key, str)
+
+	ban = key + '='
+	for x in self.env.DEFINES:
+		if x.startswith(ban):
+			return True
+	return False
+
+@conf
+def get_define(self, key):
+	"""
+	Returns the value of an existing define, or None if not found
+
+	:param key: define name
+	:type key: string
+	:rtype: string
+	"""
+	assert key and isinstance(key, str)
+
+	ban = key + '='
+	for x in self.env.DEFINES:
+		if x.startswith(ban):
+			return x[len(ban):]
+	return None
+
+@conf
+def have_define(self, key):
+	"""
+	Returns a variable suitable for command-line or header use by removing invalid characters
+	and prefixing it with ``HAVE_``
+
+	:param key: define name
+	:type key: string
+	:return: the input key prefixed by *HAVE_* and substitute any invalid characters.
+	:rtype: string
+	"""
+	return (self.env.HAVE_PAT or 'HAVE_%s') % Utils.quote_define_name(key)
+
+@conf
+def write_config_header(self, configfile='', guard='', top=False, defines=True, headers=False, remove=True, define_prefix=''):
+	"""
+	Writes a configuration header containing defines and includes::
+
+		def configure(cnf):
+			cnf.define('A', 1)
+			cnf.write_config_header('config.h')
+
+	This function only adds include guards (if necessary), consult
+	:py:func:`waflib.Tools.c_config.get_config_header` for details on the body.
+
+	:param configfile: path to the file to create (relative or absolute)
+	:type configfile: string
+	:param guard: include guard name to add, by default it is computed from the file name
+	:type guard: string
+	:param top: write the configuration header from the build directory (default is from the current path)
+	:type top: bool
+	:param defines: add the defines (yes by default)
+	:type defines: bool
+	:param headers: add #include in the file
+	:type headers: bool
+	:param remove: remove the defines after they are added (yes by default, works like in autoconf)
+	:type remove: bool
+	:type define_prefix: string
+	:param define_prefix: prefix all the defines in the file with a particular prefix
+	"""
+	if not configfile:
+		configfile = WAF_CONFIG_H
+	waf_guard = guard or 'W_%s_WAF' % Utils.quote_define_name(configfile)
+
+	node = top and self.bldnode or self.path.get_bld()
+	node = node.make_node(configfile)
+	node.parent.mkdir()
+
+	lst = ['/* WARNING! All changes made to this file will be lost! */\n']
+	lst.append('#ifndef %s\n#define %s\n' % (waf_guard, waf_guard))
+	lst.append(self.get_config_header(defines, headers, define_prefix=define_prefix))
+	lst.append('\n#endif /* %s */\n' % waf_guard)
+
+	node.write('\n'.join(lst))
+
+	# config files must not be removed on "waf clean"
+	self.env.append_unique(Build.CFG_FILES, [node.abspath()])
+
+	if remove:
+		for key in self.env[DEFKEYS]:
+			self.undefine(key)
+		self.env[DEFKEYS] = []
+
+@conf
+def get_config_header(self, defines=True, headers=False, define_prefix=''):
+	"""
+	Creates the contents of a ``config.h`` file from the defines and includes
+	set in conf.env.define_key / conf.env.include_key. No include guards are added.
+
+	A prelude will be added from the variable env.WAF_CONFIG_H_PRELUDE if provided. This
+	can be used to insert complex macros or include guards::
+
+		def configure(conf):
+			conf.env.WAF_CONFIG_H_PRELUDE = '#include <unistd.h>\\n'
+			conf.write_config_header('config.h')
+
+	:param defines: write the defines values
+	:type defines: bool
+	:param headers: write include entries for each element in self.env.INCKEYS
+	:type headers: bool
+	:type define_prefix: string
+	:param define_prefix: prefix all the defines with a particular prefix
+	:return: the contents of a ``config.h`` file
+	:rtype: string
+	"""
+	lst = []
+
+	if self.env.WAF_CONFIG_H_PRELUDE:
+		lst.append(self.env.WAF_CONFIG_H_PRELUDE)
+
+	if headers:
+		for x in self.env[INCKEYS]:
+			lst.append('#include <%s>' % x)
+
+	if defines:
+		tbl = {}
+		for k in self.env.DEFINES:
+			a, _, b = k.partition('=')
+			tbl[a] = b
+
+		for k in self.env[DEFKEYS]:
+			caption = self.get_define_comment(k)
+			if caption:
+				caption = ' /* %s */' % caption
+			try:
+				txt = '#define %s%s %s%s' % (define_prefix, k, tbl[k], caption)
+			except KeyError:
+				txt = '/* #undef %s%s */%s' % (define_prefix, k, caption)
+			lst.append(txt)
+	return "\n".join(lst)
+
+@conf
+def cc_add_flags(conf):
+	"""
+	Adds CFLAGS / CPPFLAGS from os.environ to conf.env
+	"""
+	conf.add_os_flags('CPPFLAGS', dup=False)
+	conf.add_os_flags('CFLAGS', dup=False)
+
+@conf
+def cxx_add_flags(conf):
+	"""
+	Adds CXXFLAGS / CPPFLAGS from os.environ to conf.env
+	"""
+	conf.add_os_flags('CPPFLAGS', dup=False)
+	conf.add_os_flags('CXXFLAGS', dup=False)
+
+@conf
+def link_add_flags(conf):
+	"""
+	Adds LINKFLAGS / LDFLAGS from os.environ to conf.env
+	"""
+	conf.add_os_flags('LINKFLAGS', dup=False)
+	conf.add_os_flags('LDFLAGS', dup=False)
+
+@conf
+def cc_load_tools(conf):
+	"""
+	Loads the Waf c extensions
+	"""
+	if not conf.env.DEST_OS:
+		conf.env.DEST_OS = Utils.unversioned_sys_platform()
+	conf.load('c')
+
+@conf
+def cxx_load_tools(conf):
+	"""
+	Loads the Waf c++ extensions
+	"""
+	if not conf.env.DEST_OS:
+		conf.env.DEST_OS = Utils.unversioned_sys_platform()
+	conf.load('cxx')
+
+@conf
+def get_cc_version(conf, cc, gcc=False, icc=False, clang=False):
+	"""
+	Runs the preprocessor to determine the gcc/icc/clang version
+
+	The variables CC_VERSION, DEST_OS, DEST_BINFMT and DEST_CPU will be set in *conf.env*
+
+	:raise: :py:class:`waflib.Errors.ConfigurationError`
+	"""
+	cmd = cc + ['-dM', '-E', '-']
+	env = conf.env.env or None
+	try:
+		out, err = conf.cmd_and_log(cmd, output=0, input='\n'.encode(), env=env)
+	except Errors.WafError:
+		conf.fatal('Could not determine the compiler version %r' % cmd)
+
+	if gcc:
+		if out.find('__INTEL_COMPILER') >= 0:
+			conf.fatal('The intel compiler pretends to be gcc')
+		if out.find('__GNUC__') < 0 and out.find('__clang__') < 0:
+			conf.fatal('Could not determine the compiler type')
+
+	if icc and out.find('__INTEL_COMPILER') < 0:
+		conf.fatal('Not icc/icpc')
+
+	if clang and out.find('__clang__') < 0:
+		conf.fatal('Not clang/clang++')
+	if not clang and out.find('__clang__') >= 0:
+		conf.fatal('Could not find gcc/g++ (only Clang), if renamed try eg: CC=gcc48 CXX=g++48 waf configure')
+
+	k = {}
+	if icc or gcc or clang:
+		out = out.splitlines()
+		for line in out:
+			lst = shlex.split(line)
+			if len(lst)>2:
+				key = lst[1]
+				val = lst[2]
+				k[key] = val
+
+		def isD(var):
+			return var in k
+
+		# Some documentation is available at http://predef.sourceforge.net
+		# The names given to DEST_OS must match what Utils.unversioned_sys_platform() returns.
+		if not conf.env.DEST_OS:
+			conf.env.DEST_OS = ''
+		for i in MACRO_TO_DESTOS:
+			if isD(i):
+				conf.env.DEST_OS = MACRO_TO_DESTOS[i]
+				break
+		else:
+			if isD('__APPLE__') and isD('__MACH__'):
+				conf.env.DEST_OS = 'darwin'
+			elif isD('__unix__'): # unix must be tested last as it's a generic fallback
+				conf.env.DEST_OS = 'generic'
+
+		if isD('__ELF__'):
+			conf.env.DEST_BINFMT = 'elf'
+		elif isD('__WINNT__') or isD('__CYGWIN__') or isD('_WIN32'):
+			conf.env.DEST_BINFMT = 'pe'
+			if not conf.env.IMPLIBDIR:
+				conf.env.IMPLIBDIR = conf.env.LIBDIR # for .lib or .dll.a files
+			conf.env.LIBDIR = conf.env.BINDIR
+		elif isD('__APPLE__'):
+			conf.env.DEST_BINFMT = 'mac-o'
+
+		if not conf.env.DEST_BINFMT:
+			# Infer the binary format from the os name.
+			conf.env.DEST_BINFMT = Utils.destos_to_binfmt(conf.env.DEST_OS)
+
+		for i in MACRO_TO_DEST_CPU:
+			if isD(i):
+				conf.env.DEST_CPU = MACRO_TO_DEST_CPU[i]
+				break
+
+		Logs.debug('ccroot: dest platform: ' + ' '.join([conf.env[x] or '?' for x in ('DEST_OS', 'DEST_BINFMT', 'DEST_CPU')]))
+		if icc:
+			ver = k['__INTEL_COMPILER']
+			conf.env.CC_VERSION = (ver[:-2], ver[-2], ver[-1])
+		else:
+			if isD('__clang__') and isD('__clang_major__'):
+				conf.env.CC_VERSION = (k['__clang_major__'], k['__clang_minor__'], k['__clang_patchlevel__'])
+			else:
+				# older clang versions and gcc
+				conf.env.CC_VERSION = (k['__GNUC__'], k['__GNUC_MINOR__'], k.get('__GNUC_PATCHLEVEL__', '0'))
+	return k
+
+@conf
+def get_xlc_version(conf, cc):
+	"""
+	Returns the Aix compiler version
+
+	:raise: :py:class:`waflib.Errors.ConfigurationError`
+	"""
+	cmd = cc + ['-qversion']
+	try:
+		out, err = conf.cmd_and_log(cmd, output=0)
+	except Errors.WafError:
+		conf.fatal('Could not find xlc %r' % cmd)
+
+	# the intention is to catch the 8.0 in "IBM XL C/C++ Enterprise Edition V8.0 for AIX..."
+	for v in (r"IBM XL C/C\+\+.* V(?P<major>\d*)\.(?P<minor>\d*)",):
+		version_re = re.compile(v, re.I).search
+		match = version_re(out or err)
+		if match:
+			k = match.groupdict()
+			conf.env.CC_VERSION = (k['major'], k['minor'])
+			break
+	else:
+		conf.fatal('Could not determine the XLC version.')
+
+@conf
+def get_suncc_version(conf, cc):
+	"""
+	Returns the Sun compiler version
+
+	:raise: :py:class:`waflib.Errors.ConfigurationError`
+	"""
+	cmd = cc + ['-V']
+	try:
+		out, err = conf.cmd_and_log(cmd, output=0)
+	except Errors.WafError as e:
+		# Older versions of the compiler exit with non-zero status when reporting their version
+		if not (hasattr(e, 'returncode') and hasattr(e, 'stdout') and hasattr(e, 'stderr')):
+			conf.fatal('Could not find suncc %r' % cmd)
+		out = e.stdout
+		err = e.stderr
+
+	version = (out or err)
+	version = version.splitlines()[0]
+
+	# cc: Sun C 5.10 SunOS_i386 2009/06/03
+	# cc: Studio 12.5 Sun C++ 5.14 SunOS_sparc Beta 2015/11/17
+	# cc: WorkShop Compilers 5.0 98/12/15 C 5.0
+	version_re = re.compile(r'cc: (studio.*?|\s+)?(sun\s+(c\+\+|c)|(WorkShop\s+Compilers))?\s+(?P<major>\d*)\.(?P<minor>\d*)', re.I).search
+	match = version_re(version)
+	if match:
+		k = match.groupdict()
+		conf.env.CC_VERSION = (k['major'], k['minor'])
+	else:
+		conf.fatal('Could not determine the suncc version.')
+
+# ============ the --as-needed flag should added during the configuration, not at runtime =========
+
+@conf
+def add_as_needed(self):
+	"""
+	Adds ``--as-needed`` to the *LINKFLAGS*
+	On some platforms, it is a default flag.  In some cases (e.g., in NS-3) it is necessary to explicitly disable this feature with `-Wl,--no-as-needed` flag.
+	"""
+	if self.env.DEST_BINFMT == 'elf' and 'gcc' in (self.env.CXX_NAME, self.env.CC_NAME):
+		self.env.append_unique('LINKFLAGS', '-Wl,--as-needed')
+
+# ============ parallel configuration
+
+class cfgtask(Task.Task):
+	"""
+	A task that executes build configuration tests (calls conf.check)
+
+	Make sure to use locks if concurrent access to the same conf.env data is necessary.
+	"""
+	def __init__(self, *k, **kw):
+		Task.Task.__init__(self, *k, **kw)
+		self.run_after = set()
+
+	def display(self):
+		return ''
+
+	def runnable_status(self):
+		for x in self.run_after:
+			if not x.hasrun:
+				return Task.ASK_LATER
+		return Task.RUN_ME
+
+	def uid(self):
+		return Utils.SIG_NIL
+
+	def signature(self):
+		return Utils.SIG_NIL
+
+	def run(self):
+		conf = self.conf
+		bld = Build.BuildContext(top_dir=conf.srcnode.abspath(), out_dir=conf.bldnode.abspath())
+		bld.env = conf.env
+		bld.init_dirs()
+		bld.in_msg = 1 # suppress top-level start_msg
+		bld.logger = self.logger
+		bld.multicheck_task = self
+		args = self.args
+		try:
+			if 'func' in args:
+				bld.test(build_fun=args['func'],
+					msg=args.get('msg', ''),
+					okmsg=args.get('okmsg', ''),
+					errmsg=args.get('errmsg', ''),
+					)
+			else:
+				args['multicheck_mandatory'] = args.get('mandatory', True)
+				args['mandatory'] = True
+				try:
+					bld.check(**args)
+				finally:
+					args['mandatory'] = args['multicheck_mandatory']
+		except Exception:
+			return 1
+
+	def process(self):
+		Task.Task.process(self)
+		if 'msg' in self.args:
+			with self.generator.bld.multicheck_lock:
+				self.conf.start_msg(self.args['msg'])
+				if self.hasrun == Task.NOT_RUN:
+					self.conf.end_msg('test cancelled', 'YELLOW')
+				elif self.hasrun != Task.SUCCESS:
+					self.conf.end_msg(self.args.get('errmsg', 'no'), 'YELLOW')
+				else:
+					self.conf.end_msg(self.args.get('okmsg', 'yes'), 'GREEN')
+
+@conf
+def multicheck(self, *k, **kw):
+	"""
+	Runs configuration tests in parallel; results are printed sequentially at the end of the build
+	but each test must provide its own msg value to display a line::
+
+		def test_build(ctx):
+			ctx.in_msg = True # suppress console outputs
+			ctx.check_large_file(mandatory=False)
+
+		conf.multicheck(
+			{'header_name':'stdio.h', 'msg':'... stdio', 'uselib_store':'STDIO', 'global_define':False},
+			{'header_name':'xyztabcd.h', 'msg':'... optional xyztabcd.h', 'mandatory': False},
+			{'header_name':'stdlib.h', 'msg':'... stdlib', 'okmsg': 'aye', 'errmsg': 'nope'},
+			{'func': test_build, 'msg':'... testing an arbitrary build function', 'okmsg':'ok'},
+			msg       = 'Checking for headers in parallel',
+			mandatory = True, # mandatory tests raise an error at the end
+			run_all_tests = True, # try running all tests
+		)
+
+	The configuration tests may modify the values in conf.env in any order, and the define
+	values can affect configuration tests being executed. It is hence recommended
+	to provide `uselib_store` values with `global_define=False` to prevent such issues.
+	"""
+	self.start_msg(kw.get('msg', 'Executing %d configuration tests' % len(k)), **kw)
+
+	# Force a copy so that threads append to the same list at least
+	# no order is guaranteed, but the values should not disappear at least
+	for var in ('DEFINES', DEFKEYS):
+		self.env.append_value(var, [])
+	self.env.DEFINE_COMMENTS = self.env.DEFINE_COMMENTS or {}
+
+	# define a task object that will execute our tests
+	class par(object):
+		def __init__(self):
+			self.keep = False
+			self.task_sigs = {}
+			self.progress_bar = 0
+		def total(self):
+			return len(tasks)
+		def to_log(self, *k, **kw):
+			return
+
+	bld = par()
+	bld.keep = kw.get('run_all_tests', True)
+	bld.imp_sigs = {}
+	tasks = []
+
+	id_to_task = {}
+	for dct in k:
+		x = Task.classes['cfgtask'](bld=bld, env=None)
+		tasks.append(x)
+		x.args = dct
+		x.bld = bld
+		x.conf = self
+		x.args = dct
+
+		# bind a logger that will keep the info in memory
+		x.logger = Logs.make_mem_logger(str(id(x)), self.logger)
+
+		if 'id' in dct:
+			id_to_task[dct['id']] = x
+
+	# second pass to set dependencies with after_test/before_test
+	for x in tasks:
+		for key in Utils.to_list(x.args.get('before_tests', [])):
+			tsk = id_to_task[key]
+			if not tsk:
+				raise ValueError('No test named %r' % key)
+			tsk.run_after.add(x)
+		for key in Utils.to_list(x.args.get('after_tests', [])):
+			tsk = id_to_task[key]
+			if not tsk:
+				raise ValueError('No test named %r' % key)
+			x.run_after.add(tsk)
+
+	def it():
+		yield tasks
+		while 1:
+			yield []
+	bld.producer = p = Runner.Parallel(bld, Options.options.jobs)
+	bld.multicheck_lock = Utils.threading.Lock()
+	p.biter = it()
+
+	self.end_msg('started')
+	p.start()
+
+	# flush the logs in order into the config.log
+	for x in tasks:
+		x.logger.memhandler.flush()
+
+	self.start_msg('-> processing test results')
+	if p.error:
+		for x in p.error:
+			if getattr(x, 'err_msg', None):
+				self.to_log(x.err_msg)
+				self.end_msg('fail', color='RED')
+				raise Errors.WafError('There is an error in the library, read config.log for more information')
+
+	failure_count = 0
+	for x in tasks:
+		if x.hasrun not in (Task.SUCCESS, Task.NOT_RUN):
+			failure_count += 1
+
+	if failure_count:
+		self.end_msg(kw.get('errmsg', '%s test failed' % failure_count), color='YELLOW', **kw)
+	else:
+		self.end_msg('all ok', **kw)
+
+	for x in tasks:
+		if x.hasrun != Task.SUCCESS:
+			if x.args.get('mandatory', True):
+				self.fatal(kw.get('fatalmsg') or 'One of the tests has failed, read config.log for more information')
+
+@conf
+def check_gcc_o_space(self, mode='c'):
+	if int(self.env.CC_VERSION[0]) > 4:
+		# this is for old compilers
+		return
+	self.env.stash()
+	if mode == 'c':
+		self.env.CCLNK_TGT_F = ['-o', '']
+	elif mode == 'cxx':
+		self.env.CXXLNK_TGT_F = ['-o', '']
+	features = '%s %sshlib' % (mode, mode)
+	try:
+		self.check(msg='Checking if the -o link must be split from arguments', fragment=SNIP_EMPTY_PROGRAM, features=features)
+	except self.errors.ConfigurationError:
+		self.env.revert()
+	else:
+		self.env.commit()
+